Hi, > -----Original Message----- > From: Keith Busch <kbusch@xxxxxxxxxx> > Sent: Friday, February 14, 2025 12:07 AM > To: lizetao <lizetao1@xxxxxxxxxx> > Cc: Keith Busch <kbusch@xxxxxxxx>; io-uring@xxxxxxxxxxxxxxx; > axboe@xxxxxxxxx > Subject: Re: [PATCHv2 0/6] ublk zero-copy support > > On Thu, Feb 13, 2025 at 03:12:43PM +0000, lizetao wrote: > > I tested this patch set. When I use null as the device, the test results are like > your v1. > > When the bs is 4k, there is a slight improvement; when the bs is 64k, there is > a significant improvement. > > However, when I used loop as the device, I found that there was no > improvement, whether using 4k or 64k. As follow: > > > > ublk add -t loop -f ./ublk-loop.img > > ublk add -t loop -f ./ublk-loop-zerocopy.img > > > > fio -filename=/dev/ublkb0 -direct=1 -rw=read -iodepth=1 -ioengine=io_uring > -bs=128k -size=5G > > read: IOPS=2015, BW=126MiB/s (132MB/s)(1260MiB/10005msec) > > > > fio -filename=/dev/ublkb1 -direct=1 -rw=read -iodepth=1 -ioengine=io_uring > -bs=128k -size=5G > > read: IOPS=1998, BW=125MiB/s (131MB/s)(1250MiB/10005msec) > > > > > > So, this patch set is optimized for null type devices? Or if I've missed any key > information, please let me know. > > What do you get if if you run your fio job directly on your ublk-loop.img file? I test it directly on ublk-loop.img, and the result is as follow: fio -filename=./ublk-loop.img -direct=1 -rw=read -iodepth=1 -ioengine=io_uring -bs=128k -size=5G read: IOPS=1005, BW=126MiB/s (132MB/s)(1258MiB/10009msec)
